.

Author: anforowicz

text/0000-export-visibility.md

@@ -285,8 +285,17 @@ and
 [`#[export_name = ...]`](https://doc.rust-lang.org/reference/abi.html#the-export_name-attribute)
 attributes provides a similar level of details.)
 
-> **Note**: The proposal in this RFC has been prototyped in
->  https://github.com/anforowicz/rust/tree/export-visibility
+A few additional notes attempt to clarify the intended behavior of the proposed
+behavior beyond what is described in the guide-level explanation above:
+
+* The `#[export_visibility = ...]` attribute may only be applied to item
+  definitions with an "extern" indicator as checked by
+  [`fn contains_extern_indicator`](https://github.com/rust-lang/rust/blob/3bc767e1a215c4bf8f099b32e84edb85780591b1/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs#L174-L184).
+  Therefore it may only be applied to items to which
+  `#[no_mangle]`, `#[export_name = ...]`, and similar already-existing
+  attributes may be already applied.
+* The proposal in this RFC has been prototyped in
+  https://github.com/anforowicz/rust/tree/export-visibility
 
 # Drawbacks
 [drawbacks]: #drawbacks